if a plan or method works like a charm, it has exactly the effect that you want it to.

I tried that stain remover you gave me on my tablecloth and it worked like a charm.

• too good to be true
• too hot to handle
• too little, too late
• tools of the trade
• tools of trade
• tools of your trade
• too many chiefs
• too many chiefs and not enough Indians
• Too many cooks .
• Too many cooks spoil the broth.
• too much of a good thing
• too something for words
• top brass
• top dog
• top-drawer
• top-flight
• top flight
• top it all
• top it all off
• top-notch
• top off
• top off something
• top of the heap
• top of the hour
• top of the ladder